Hi everyone,
At the request of Krishna Sankar of Cisco, here is a brief synopsis of HP's
Web Services Transactions product intended to foster further discussion on
how BTP might fit into the larger Web Services picture.
From an earlier email to the SOAP discussion list:
HP-WST provides:
(i) Simple to use API for managing transactions from client applications;
(ii) Non-invasive infrastructure for transactionalising existing Web
Services;
(iii) Infrastructure for creating transaction participants to support
transactional Web Services; and
(iv) A transaction manager which can coordinate BTP-like transactions.
So what WST provides is an OASIS BTP-based transaction manager and
infrastructure to hook Web Services into WST transactions. Essentially the
transaction manager coordinates the activities of an application's
constiuent Web Services so that they are kept in step with one another.
The messages in BTO exchanges are XML encoded, but BTP does not mandate any
particular transport mechanism for this. For WST we chose SOAP over HTTP.
So far no real magic, but what makes BTP useful is its transaction model.
There are four primary requirements that BTP has been designed to deal with:
1) Ability to handle multiple successful outcomes to a transaction, with the
ability to involve operations whose effects may not be isolated or durable.
2) Coordination of autonomous parties whose relationships are governed by
contracts rather than the dictates of a central design authority.
3) Discontinuous service, where parties are anticipated to suffer outages
during their lifetime, and coordinated work must be able to survive such
outages.
4) Interoperation using XML over multiple communication protocols.
Now to my (naÂ´ve) mind these requirements seem very complimentary to the Web
Services architecture.
Jim
--
Dr. Jim Webber
Hewlett-Packard Arjuna Lab
http://www.arjuna.com